1. Field of the Invention
The present invention is in the field of off-shore oil production, and, more particularly, is in the field systems to recover oil released proximate to the sea bed.
2. Description of the Related Art
Off-shore drilling for oil below the sea bed is an important part of world-wide energy production. For deep-water exploration, a typical off-shore oil drilling system includes a floating platform (or rig) that is anchored (tethered) to the sea bed to secure the platform at a particular location over the sea bed. The well is drilled through a blowout preventer or other structure on the sea bed that is intended to prevent an inadvertent discharge of pressurized oil from the well if an unexpected increase in pressure causes oil to rise in the annular space between the casing and the drill pipe within the casing. Blowout preventers generally operate as intended; however, when a blowout preventer does not work as intended, oil can escape from the well into the water surrounding the well. In some cases, particularly at great depths, the oil may continue to escape for extended periods. For example, the Deepwater Horizon oil spill in the Gulf of Mexico started with an explosion on Apr. 20, 2010, and released oil into the Gulf of Mexico until at least Jul. 15, 2010. During that time, many attempts were made to stop the release by capping the wellhead. In the meantime, many millions of barrels of oil spread throughout the Gulf of Mexico. Although considerable efforts were made to constrain the spread of the oil and to recover part of the oil, the oil spread rapidly and reached the shorelines, thus causing extensive damage to the ocean environment and to the shorelines.